Effect of the Drying Method and Storage Conditions on the Quality and Content of Selected Bioactive Compounds of Green Legume Vegetables.

This study aimed to determine the effect of the drying method (freeze-drying, air-drying), storage period (12 months), and storage conditions (2-4 °C, 18-22 °C) applied to two legume species: green beans and green peas. The raw and dried materials were determined for selected physical parameters typical of dried vegetables, contents of bioactive components (vitamin C and E, total chlorophyll, total carotenoids, ß-carotene, and total polyphenols), antioxidative activity against the DPPH radical, and sensory attributes (overall quality and profiles of color, texture, and palatability). Green beans had a significantly higher content of bioactive components compared to peas. Freeze-drying and cold storage conditions facilitated better retention of these compounds, i.e., by 9-39% and 3-11%, respectively. After 12 months of storage, higher retention of bioactive components, except for total chlorophyll, was determined in peas regardless of the drying method, i.e., by 38-75% in the freeze-dried product and 30-77% in the air-dried product, compared to the raw material.

Changes due to cooking and sterilization in low molecular weight carbohydrates in immature seeds of five cultivars of common bean.

Immature seeds of five bean cultivars (flageolet-type and those intended for dry-seed production) were assessed for changes in water-soluble carbohydrates including raffinose family oligosaccharides (RFOs) due to boiling, sterilization, and storage of the sterilized product. About 100 g fresh weight of edible portion of fresh bean seeds contained 2449.3-3182.6 mg total soluble sugars, of which RFOs comprised 44-49%. The highest amounts of these compounds were found in the seeds of the cultivars Laponia and Mona. The dominant oligosaccharide was stachyose. Boiling fresh seeds to consumption consistency reduced total soluble sugars and RFOs: average values were 57% and 55%, respectively. Sterilization in cans resulted in 65% reductions of both total soluble sugars and RFOs. In general, there were no changes in the content of soluble sugars in canned and sterilized products stored for 12 months.

Effect of the method of preparation for consumption on calcium retention, calcium:phosphorus ratio, nutrient density and recommended daily allowance in fourteen vegetables.

The aim of this work was to evaluate calcium retention in 14 species of vegetable (from four usable groups). The material investigated consisted of raw and boiled fresh vegetables and two types of frozen product prepared for consumption after 12-month storage: one traditionally produced; the other obtained using the modified method (convenience food). The highest calcium content was found in leafy vegetables, followed (in descending order) by leguminous, root and brassica vegetables. The proportion by weight of Ca to P was highest in leafy vegetables and decreased with calcium retention despite the fact that levels of phosphorus were highest in leguminous and lowest in leafy vegetables. The nutrient density (ND%) of calcium for adults exceeded 100 for each individual vegetable species. The recommended daily allowance (RDA) percentage value varied between 23.04 (kale) and 1.46 (white cauliflower). Of the three types of product, ND and RDA values were generally greater in the frozen convenience products.

Zinc retention in vegetables according to the method of preparation for consumption.

The aim of the present work was to evaluate the retention, the nutrient density and the recommended daily allowance of zinc in 14 common vegetable species prepared for consumption. The investigation included fresh vegetables, vegetables after traditional cooking in brine and two types of frozen products: one obtained using the traditional method (blanching-freezing-storage-cooking in brine) and the other obtained using the modified method, providing a ready-to-eat product (cooking in brine-freezing-storage-defrosting and heating in a microwave oven). A significant zinc decrease was found in most studied vegetables prepared for consumption. Application of the modified method contributed to a reduction in zinc losses in prepared-for-consumption frozen vegetables.

Effect of maturity stage on the content of ash components in raw and preserved grass pea (Lathyrus sativus L.) seeds.

The grains of grass pea cultivar krab of dry matter content at the level of 26-40 g/100 g were used in the production of preserves by freezing and canning in air tight containers. The content of ash and its alkalinity and of potassium, magnesium, calcium, iron, total phosphorus, and phytic phosphorus was determined in raw and blanched material, in frozen products stored for six months and then cooked to consumption consistency, and in sterilized canned products after the same storage period. With the increasing degree of maturity the content of all the above constituents calculated per 100 g fresh matter, increased. Blanching considerably reduced the level of ash and its alkalinity, of potassium, and of phytic phosphorus. The cooking of frozen seeds and the sterilization in salty brine caused a reduction of the components analysed except for the content of ash, its alkalinity, and of calcium. In comparison with canned sterilized preserves in cooked frozen grains a higher content of all the mineral components was determined.